Three wheel aerial platform apparatus

ABSTRACT

A three wheel aerial platform apparatus has a pair of aligned wheels at one end, a powered, steered single wheel at the other end and a boom having a platform at its free end. The chassis comprises a pair of closely spaced vertical upright plates, the boom being between these uprights and carried on a horizontal pivot generally above the single wheel, the boom extending toward the dual wheels. The boom pivot is outside the wheel-base. An engine and pump are supported on the outside of one upright, and tanks are supported on the outside of the other upright. The pair of wheels are carried outside the uprights on identical off-set axle assemblies having support bars extending into a pair of hollow, superposed beams extending transversely of the uprights, vertical transverse members joined to the support bars supporting the axles on a common axis. The single wheel is steered by an expansible hydraulic motor which rotates a sector gear in mesh with a pinion gear on a stub shaft which supports the single wheel. The stub shaft is journalled in a slab providing an integral counterweight and chassis member.

Grove Dec. 24, 1974 THREE WHEEL AERIAL PLATFORM APPARATUS [75] Inventor: John L. Grove, McConnellsburg,

[73] Assignee: Fulton Industries, Inc.,

McConnellsburg, Pa.

[22] Filed: May 25, 1973 [21] Appl. No.: 364,194

[52] US. Cl, 182/16, 182/2, 182/63, 182/141, 280/34 R [51] Int. Cl B66f 11/04 [58] Field of Search 182/2, 141, 148, 12, 16, 182/63; 280/34R, 34 A, 62, 1 F, 25 R, 27

[56] 1 References Cited UNITED STATES PATENTS 2,767,995 10/1956 Stout 280/34 R 2,821,312 1/1958 Wiegel 182/2 2,857,725 10/1958 Canfield.... 280/34 R 2,954,092 9/1960 Trump 182/2 2,970,667 2/1961 Bercaw 182/2 3,243,123 3/1966 lngraham 182/2 3,319,739 5/1967 Morse 182/2 3,532,307 10/1970 Larson 280/34 R Primary Examiner-Reinaldo P. Machado Attorney, Agent, or Firm-1rvin A. Lavine [57] ABSTRACT A three wheel aerial platform apparatus has a pair of aligned wheels at one end, a powered, steered single wheel at the other end and a boom having a platform at its free end. The chassis comprises a pair of closely spaced vertical upright plates, the boom being between these uprights and carried on a horizontal pivot generally above the single wheel, the boom extending toward the dual wheels. The boom pivot is outside the wheel-base. An engine and pump are supported on the outside of one upright, and tanks are supported on the outside of the other upright. The pair of wheels are carried outside the uprights on identical off-set axle assemblies having support bars extending into a pair of hollow, superposed beams extending transversely of the uprights, vertical transverse members joined to the support bars supporting the axles on a common axis. The single wheel is steered by an expansible hydraulic motor which rotates a sector gear in mesh with a pinion gear on a stub shaft which supports the single wheel. The stub shaft is journalled in a slab providing an integral counterweight and chassis member.

18 Claims, 5 Drawing Figures PATENTEH "53245174 sum 2 m 3 MGR PATENTED UEC24 I974 snmaum BACKGROUND OFTHE INVENTION The present invention relates to aerial platform apparatus, and more particularly to aerial platform apparatus which is supported by three ground-engaging wheels.

'Aerial platforms have found wide utility in industry and agriculture over the past years. Many such apparatus have been proposed which include a chassis with two front and two rear wheels, a boom supported on the chassis, usually for both luffing and swinging movement, and a platform supported at the upper or free end of the boom. Other proposals have provided aerial platform apparatus including only three ground engaging wheels. These are typically smaller machines, wherein there is provided a pair of generally aligned wheels at one end of the machine, and a single wheel at the other end, supported for movement about a vertical pivot, to permit steering. -While some of the smaller machines have provided for swinging movement of the boom, relative to the chassis, in the majority of machines which have been suggested, the maneuverability of the vehicle, achieved through the three wheel construction has been relied upon to effect lateral movement of the workmans platform. It is known to drive the dual wheels, by individual control, with the single wheel being .free to, caster,,while in other suggested constructions, the single wheel has been both driven and steered, by power means.

The three wheel machines which have heretofore been proposed have had an excessive width, in order to achieve stability, the maximum width being provided bythe distance between the dual wheels. This distance has been, for example, some times greater than the width of the boom itself, thereby greatly restricting the utility of such machines, since they were not able to be moved through narrow spaces, such as conventional doorways found in industrial installations.

Some prior art machines have been provided with extendable axle constructions for the dual wheels, in order to provide increased stability, but even such machines did not have a relatively small overall minimum width. Further, such known machines have placed the mechanical equipment, such as the engines, pumps and motors in positions which were relatively inaccessible for servicing, often requiring that a service man place himself within the boundaries of the chassis in order to service such mechanical equipment.

A problem which faces the constructor of such machines is the danger that the machine may tip over, when the aerial platform is at its greatest reach beyond the end of the machine, the machine rotating, in a typical construction, about the dual wheels. Further, in the SUMMARY OF THE INVENTION A three wheel aerial platform apparatus is provided, having a chassis characterized by a pair of spaced, substantially parallel upright plates, These plates are' closely spaced, and atone end, a boom is mounted on a horizontal pivot, the boom being extensible, and carrying'on its outer or free end a workmans platform.

The platform is provided with controls for moving the boom, and for moving the entire apparatus. A pair of dual wheels are provided at the end of the plates opposite to the boom pivot, these wheels being on the outside of the uprights. At the end carrying theboom pivot, the plates are cut away to provide a wheel well construction in which there is mounted a single wheel, carried by a fork which includes a stub axle, the fork having a drive motor mounted on it for driving the single wheel, and the stub axle extending generally vertically, and between the plates. The stub axle is supported in a horizontal slab extending between the upright plates, this slab being a heavy mass and providing an integral counter-weight and chassis member extending between the uprights and having the stub shaft journalled in it. The axis of the stub shaft is positioned relative to a vertical plane containing the horizontal boom pivot so that the latter lies outside of the wheel base, to increase stability. The stub axle is rotated, to provide steering of the machine, by an apparatus which includes a linearly extensible hydraulic motor which is connected to a sector gear, the sector gear being in mesh with a pinion gear mounted on the stub axle.

On the outside of one of the upright plates, within the wheel base, there is mounted an engine and a pump, and on the outside of the other upright plate, opposite to the engine and pump, there are mounted tanks, for fuel and for hydraulic oil, with appropriate conduits extending therebetween.

A pair of hollow beams are provided, one above the other, at the end of the upright plates remote from the boom pivot, each supporting one of a pair of substantially identical off set axle assemblies. Each axle assembly includes an outwardly extending axle on which one of the dual wheels is journalled, a vertically extending transverse member at the inner end of the wheel axle,

and a support bar extending from the transverse member, oppositely to and off-set from the axle, the support bar extending into a hollow beam, with which it has substantially mating engagement. The support bar preferably has a length substantially equal to the length of the hollow beam, and at least has a length more than /2 of the hollow beam. The vertical distance between the axis of a support bar and the wheel axis to which it is connected is substantially equal to /2 'of the depth of a hollow beam, the two hollow beams being substantially identical.

Among the objects of the present invention are to provide a three wheel machine of narrow construction.

Another object of the present invention is the provi sion of a three wheel machine of narrowconstruction and having the wheels thereof extendable for stability.

Yet another object of the present invention is to provide a three wheel aerial platform apparatus having the mechanical equipment disposed to permit easy access for maintenance and repair.

Another object of the present invention is the provi-' sion of a machine of this type having an extensible boom, and having great stability againsttipping about ground-engaging wheels; a further object is to provide such a machine having an integral chassis member and counterweight.

Yet another object of the present invention is to provide a three wheel aerial platform having a steering construction utilizing a relatively economical low torque motor.

A further object of the present invention is the provision of an extensible axle construction having high strength, low cost, and substantially identical parts, while providing stability by having a common axis for the wheel axles.

' Other objects and many of the attendant advantages of the present inventionwill be readily apparent from the following specification, claims and drawings.

, BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view, withparts broken away, of a three wheel 'elevational machine in accordance with the present invention.

FIG. 2 is a plan view of the three wheel aerial platform apparatus shown FIG. 1, with parts in phantom lines.

FIG. 3 is a view taken on the line 33 of FIG. 1. FIG. 4 is a view taken on the line 44 of FIG. 2. FIG. 5 is a cross sectional view taken on the line 55 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT 4 upright plates 16 and 17, as shownin FIG. 2. The boom 20, as may be seen in FIG. 1, extends somewhat below the upper inclined edge 16 A of the upright plate 16 when in the down position shown in FIG. 1, thereby substantially closing the space between the upright plates 16 and 17, to minimize weathering and the danger'of foreign objects entering into the space between theupright plates 16. and 17.

As shown at the left end of FIG. 1, the single wheel 13 is supported by a fork 31, shown broken away to reveal a drive motor 32 for the wheel 13, motor 32 being a hydraulic motor and having connection to a pump through lines 33. At. the upper end of the fork 31, there is a vertically extending stub shaft 34 journalled in a slab 35. Slab 35 extends horizontally between the upright plates 16 and 17, and is an integral counterweight and chassis member. It may be, for example, approximately 4 inches in thickness, and is of considerably greater strength than is required by conventional stress considerations. As shown in FIG. 2, it is provided with an opening 36 in which is placed suitable bearings 37 for journalling the stub shaft 34. As is clearly shown in 7 FIG. 2, the wheel base extends from the axis of the stub by a powered and steerable wheel 13. These wheels support a chassis generally designated l5,-of which one of a pair of upright plates 16 may be seen. The plate 16, and corresponding plate 17 (FIG. 2) is cut away adjacent the single wheel 13 to provide a wheel well configuration,.generally designated 18. The chassis plates 16 and 17 each has 'substantiallyall of the structural material thereof in a vertical plane, although they may also have inturned flanges such as flanges 16', '17 extending along the upper, inclined edges thereof. The vertical height of the chassis plates 16 and 17 is non-uniform from end to end, being greatest intermediate the ends thereof. A boom 20 is provided, and includes a base section 21 having a fly section 22 telescopically received therein, and being capable of being extended from the base section 21 by conventional apparatus such as a hydraulic cylinder, not shown. At its forward end, the fly section 22 carries a connector 23 which supports a post 24 for movement about a horizontal pivot 24 A. A workmans platform 25 is carried on the post 24, being supported in conventional manner by collars 25 A and 25 B. Suitable controls 26 are provided, by which a workman on the platform 25 may raise and lower the boom 20, cause movement of the vehicle in either direction, and cause steering movement of the single wheel 13.

i The boom 20 may be raised and lowered, as to the position indicated in dotted lines in FIG. 1, by a lift cylinder 27. Pivot ally connected to the rear of the boom 20 is a master levelling cylinder 28 which is connected in known manner to a slave, levelling cylinder (not shown) which effects rotation of platform 25 about the pivot 24 A, to maintain it level in any position of the boom 20. As will be understood, the boom 20 rotates about a horizontal pivot 30 which extends through the shaft 34 to the axis of the wheels '11 and 12, and the pivot 30 for the boom 20 lies outside of this wheel base.

This provides greater resistance to tipping of the apparatus 10 about the wheels 11 and 12, it being appreciextend between the pump 42 and the various hydraulically operated motors, such as the drive motor 32 and the lift cylinder 2 7,'and also to'the controls 26, which include suitable valves. Oppositethe compartment is a compartment 45, on the outside of the upright plate 17, and within the compartment 45 there are provided tanks 46 and 47, one containing the fuel for the engine 41, and the other serving as a sump for the pump 42. As will be understood, conduits extend between the apparatus in the compartments 40 and 45, being beneath the boom 20 when. it is in the lowermost position thereof, as shown in FIG. 1. Further, the compartment 40 is provided with movable portions, so that when maintenance and repair are required, these movable portions are displaced so as to provide ready access to the engine 41 and pump 42.

Referring now to FIG. 3, there is shown a hydraulic motor 50.comprising a cylinder51 pivotally connected by a collar 52 to a pin 53 which is supported from the chassis 15 in any suitablemanner, and which extends vertically. Within the cylinder 51 is a piston 54 having a piston rod 55 connected to it, at its free end piston rod 55 being pivotally connected to a sector gear 56. A shaft 57 supported by slab 35 has sector gear 56 journalled on it, and sector gear 56 is in mesh with a pinion 58 secured to a stub shaft 34. By this construction, the linearly extensible hydraulic motor may be of relatively low torque, and therefore of economical construction. As will be understood, by manipulation of controls 26 on the platform 25, hydraulic fluid from the pump 42 may be selectively admitted to the hydraulic motor 50,-to effect steering of the single wheel 13.

Referring now to FIGS. 4 and 5, there is shown the extensible axle construction of thedual wheels-the dual wheel 12 being shown in these Figures. There are provided an upper box beam 60 and a contiguous lower box beam 61 of hollow, generally rectangular configuration (see also FIG. 1) these box beams extending normally between and being secured to the upright plates 16 and 17. Consequently, they form part of the chassis 15. An axle assembly 65 is supported by each of the box beams-60 and 61, and while one axle assembly 65 "is shown in FIG. 4, it will be understood that there is a substantially identical and interchangeable axle assembly 65 for carrying the wheel 11. The axle assembly 65 includes an axle 66, a vertical plate'67, also shown in FIG. 5, and a support bar 68..Support bar 68 has a rectangular cross section shape as shown in FIG. 5, and is received in mating relationship in the hollow beam 60, support bar 68 having a length substantially equal to the length of box beam 60. As is apparent from FIGS. 4 and 5, the axle assembly 65 is off-set, the axis of the axle 66 being vertically spaced below the axis of support bar 68. The distance between the axis of axle 66 and the axis of support bar 68 is substantially one-half of the height of the box beam 60, so that the axis of axle 66 extends in the plane which is the lower surface of upper box beam 60 andthe upper surface of lower box FIG. 2. When the apparatus 10 has passed through a narrow door or aisle, and has reached its working station, the wheels maybe extended substantially, and then the boom may be raised and extended, and the single wheel 13 may be driven and steered, in order to place the platform at a desired location. The driving,

steering,- boom movement and boom extension may all be controlled from the platform 25. Tipping moments occurring, as when the boom is fully extended,-andin beam 61. Thus, the box beams 60 and 61 will be seen to be in contacting relationship, and as will be understood, while the axle 66 for the wheel 12 is below the axis of the support bar 68, for the wheel 11, the support bar 68 thereof will extend into the lower box beam 68 and the transverse plate 67 will extend therefrom upwardly, rather than downwardly as is the case with the support bar'68 for the wheel 12. Consequently, because the axle-to-support bar distance of the two axle assemblies 65 is substantially identical, the axis of the axle 66 for the wheel 12 will coincide, substantially, with the axis of the axle 66 of the wheel 11. This achieves easier steering, avoids off-set axes of the wheel axles, and provides a strong structural constructron.

The journalling of the wheels. 12 on the axle 66 is conventional, and includes a hub 70, rim 71 and pneumatic tire 72. There is also provided a brake drum 73 and conventional brake shoes (not shown) which are actuated to brake releasing position upon the supplying of hydraulic fluid to the brake cylinder 74.

As will be understood, the width of the three wheel aerial platform apparatus 10, with the wheels 11 and 12 in the positions shown in FIG. 2 is established by the outside surfaces of the wheels 11 and 12. Due to the hereinabove set forth construction, this width may be very narrow, permitting the apparatus 10 to travel through narrow doorways and passageways. For example, in an apparatus 10, having the floor of the platform 25 l8'feet above ground, with a boom at an angle of 70 degrees to the horizontal, the width of the apparatus 10 is less than five feet. By sliding the support bars 68 outwardly, a stabilizing width of almost eight feet is obtained. Suitable lock pins or the like may be provided -to lock the support bars 68 in one or another selected position within the box beams 60 and 61.

a horizontal or near horizontal position, are counteracted by the counterweight 35, and by the location of the boom pivot 30 outside the wheel base. The placement of the mechanical equipment such as the engine, pump and their supply tanks on the outside of the upright plates provides for ready access, for maintenance and repair. The present apparatus is characterized by a chassis including a pair of vertical, closely spaced plates, so that the overall width of the apparatus is small. The construction of the steering, utilizing a sector gearand pinion, enables the utilization of a low cost, low torque hydraulic motor.

The present apparatus also provides a unique, strong and high strength extensible axle construction. Maximum possible extension of the wheel is achieved, through a simple, identical axle assembly enabling th wheels to lie on a common axis.

It will be obvious to those skilled in the art that various changes may be made without departing from the spirit of the invention and therefore the invention is not limited to what is shown in the drawings and described in the specification but only as indicated in the ap- The three wheel aerial platform apparatus 10 may be 6 driven and steered from the platform 25, with the wheels 11 and 12 in the retracted position as shown in pended claims.

I claim: 1. A three wheel aerial platform apparatus compris- -a chassis comprising a pair of spaced, substantially parallel and planar uprights, i said planar uprights each having substantially all of the structural material thereof in a vertical plane,

a wheel'on the outside of each said upright at one end thereof, means on said uprights at said one end for supporting said wheels,

a single wheel at the other end of said uprights, means on said uprights at the said other end thereof for supporting said single wheel for steering movement,

a boom, means located generally above said single wheel for horizontally pivotally supporting one end of said boom on and between said uprights, said boom extending from said pivotal means in the direction of said first mentioned wheels, a workman s platform supported at the opposite end of said boom,

and means for moving said boom.

2. The three wheel aerial platform of claim 1, and further comprising an engine supported on the outside of a said upright.

3. The three wheel aerial platform of claim 2, and a tank supported on the outside of the other said upright.

comprises a solid metal counter-weight slab extending between said uprights at said other end thereof.

6. The three wheel aerial platform of claim 5, said single wheel supporting means further comprising a stub shaft extending substantially vertically, and means journalling said stub shaft in said counter-weight slab, the horizontal pivotal axis of said boom being in a vertical plane spaced from said stub shaft and remote from said first mentioned wheels.

7. The three wheel aerial platform of claim 1, said single wheel supporting means comprising a-substantially vertically extending stub shaft, the horizontal pivotal axis of said boom being in a vertical plane spaced from said stub shaft and remote from said first mentioned wheels.

8. The three wheel aerial platform of claim 1, said single wheel supporting means further comprising a stub shaft extending substantially vertically, a pinion gear secured to said stub shaft, a sector gear pivotally supported on said apparatus and in mesh with said pinion, and expansible hydraulic motor means on said apparatus having one end secured to said sector gear remote from the pivot thereof and the other end secured to said apparatus.

9. The three wheel aerial platform of claim 1, wherein said means for supporting said outside wheels comprises means for supporting said wheels at different distances from said uprights.

10. The three wheel aerial platform of claim 9, said last mentioned means comprising a pair of hollow beams extending transversely of said uprights.

11. The three wheel aerial platform of claim 10, said hollow beams lying one above the other.

12. The three wheel aerial platform of claim 11, and

further comprising a pair of substantially identical and interchangeable off-set axle means each including an axle having a said wheel journalled thereon, a transverse member at the inner end of said axle, and a support bar extending from said member opposite to said axle and into a said hollow beam.

13. In a vehicle having a pair of spaced longitudinal members, an extendible axle construction comprising:

a. a pair of hollow beams extending normally of said longitudinal members, one above the other, b. a pair of substantially identical and interchangeable off-set axle means each including: i. an outwardly extending axle for journalling a wheel, ii. a transverse member at the inner end of said axle, and iii. a support bar extending from said member opposite to said axle and into a said hollow beam,

0. the vertical distance from axle to support bar of said two axel means being substantially equal.

14. The structure of claim 13, wherein said support bar has a length greater than one-half the length of a said hollow beam.

15. The structure of claim 14, wherein said axles lie on a common axis.

16. The structure of claim 13, wherein said axles lie on a common axis.

17. The structure of claim 13, wherein the vertical distance between the axis of said axle and the axis of said support bar is approximately /2 the height of a hollow beam.

18. The three wheel aerial platform apparatus of claim 1, wherein said planar uprights are of nonuniform vertical height between the ends thereof. 

1. A three wheel aerial platform apparatus comprising: a chassis comprising a pair of spaced, substantially parallel and planar uprights, said planar uprights each having substantially all of the structural material thereof in a vertical plane, a wheel on the outside of each said upright at one end thereof, means on said uprights at said one end for supporting said wheels, a single wheel at the other end of said uprights, means on said uprights at the said other end thereof for supporting said single wheel for steering movement, a boom, means located generally above said single wheel for horizontally pivotally supporting one end of said boom on and between said uprights, said boom extending from said pivotal means in the direction of said first mentioned wheels, a workman''s platform supported at the opposite end of said boom, and means for moving said boom.
 2. The three wheel aerial platform of claim 1, and further comprising an engine supported on the outside of a said upright.
 3. The three wheel aerial platform of claim 2, and a tank supported on the outside of the other said upright.
 4. The three wheel aerial platform of claim 3, said engine lying intermediate the ends of said upright.
 5. The three wheel aerial platform of claim 1, wherein said means for supporting said single wheel comprises a solid metal counter-weight slab extending between said uprights at said other end thereof.
 6. The three wheel aerial platform of claim 5, said single wheel supporting means further comprising a stub shaft extending substantially vertically, and means journalling said stub shaft in said counter-weight slab, the horizontal pivotal axis of said boom being in a vertical plane spaced from said stub shaft and remote from said first mentioned wheels.
 7. The three wheel aerial platform of claim 1, said single wheel supporting means comprising a substantially vertically extending stub shaft, the horizontal pivotal axis of said boom being in a vertical plane spaced from said stub shaft and remote from said first mentioned wheels.
 8. The three wheel aerial platform of claim 1, said single wheel supporting means further comprising a stub shaft extending substantially vertically, a pinion gear secured to said stub shaft, a sector gear pivotally supported on said apparatus and in mesh with said pinion, and expansible hydraulic motor means on said apparatus having one end secured to said sector gear remote from the pivot thereof and the other end secured to said apparatus.
 9. The three wheel aerial platform of claim 1, wherein said means for supporting said outside wheels comprises means for supporting said wheels at different distances from said uprights.
 10. The three wheel aerial platform of claim 9, said last mentioned means comprising a pair of hollow beams extending transversely of said uprights.
 11. The three wheel aerial platform of claim 10, said hollow beams lying one above the other.
 12. The three wheel aerial platform of claim 11, and further comprising a pair of substantially identical and interchangeable off-set axle means each including an axle having a said wheel journalled thereon, a transverse member at the inner end of said axle, and a support bar extending from said member opposite to said axle and into a said hollow beam.
 13. In a vehicle having a pair of spaced longitudinal members, an extendible axle construction comprising: a. a pair of hollow beams extending normally of said longitudinal members, one above the other, b. a pair of substantially iDentical and interchangeable off-set axle means each including: i. an outwardly extending axle for journalling a wheel, ii. a transverse member at the inner end of said axle, and iii. a support bar extending from said member opposite to said axle and into a said hollow beam, c. the vertical distance from axle to support bar of said two axel means being substantially equal.
 14. The structure of claim 13, wherein said support bar has a length greater than one-half the length of a said hollow beam.
 15. The structure of claim 14, wherein said axles lie on a common axis.
 16. The structure of claim 13, wherein said axles lie on a common axis.
 17. The structure of claim 13, wherein the vertical distance between the axis of said axle and the axis of said support bar is approximately 1/2 the height of a hollow beam.
 18. The three wheel aerial platform apparatus of claim 1, wherein said planar uprights are of non-uniform vertical height between the ends thereof. 